Article of footwear with traction system

ABSTRACT

An article of footwear with a traction system. The traction system includes a plurality of traction elements of various heights on the outsole that undergo rotation within the penetrated substratum while avoiding damage from digging the surface while walking. The plurality of traction elements has a shortened height at pivot points of a foot and a lengthened height away from the pivot points of the foot.

CROSS REFERENCE

This application is a Continuation of co-pending and co-assigned U.S.patent application Ser. No. 17/497,275 filed on Oct. 8, 2021, which isincorporated herein by reference in its entirety for all purposes.

BACKGROUND

The disclosure relates generally to the field of footwear. Morespecifically, the disclosure relates to footwear with a traction system.

Spikeless golf shoes have been increasing in popularity as they provideseveral advantages over their spiked counterparts, including increasedcomfort and versatility. In efforts to improve traction, these shoeshave increased the aggressiveness of their spikeless outsole aesthetics(including rising size, jaggedness, and number of traction elements).However, the increased aggressiveness of these traction elements hascome at the cost of damaging golf greens due to penetration of thetraction elements into the ground substratum of the greens.

SUMMARY

To this end, the present disclosure provides for an article of footwearwith high traction that reduces damage to surfaces, such as a golfgreen, while walking and playing golf. The following presents asimplified summary of the disclosure in order to provide a basicunderstanding of some aspects of the disclosure. This summary is not anextensive overview of the disclosure. It is not intended to identifycritical elements of the disclosure or to delineate the scope of thedisclosure. Its sole purpose is to present some concepts of thedisclosure in a simplified form as a prelude to the more detaileddescription that is presented elsewhere.

Accordingly, one aspect of the present disclosure is directed to anarticle of footwear configured to provide stability and traction whilewalking on a surface. In some embodiments, the article of footwear maycomprise an upper, an outsole, a midsole and a traction system.

The traction system may include a plurality of traction elements ofvarious heights on the outsole. The traction elements have a shortenedheight at pivot points of a foot and a lengthened height away from thepivot points of the foot. While walking, the traction elements undergorotation within the penetrated ground substratum while avoiding damagefrom digging the surface while walking. The plurality of tractionelements may have a shortened height at pivot points of a foot and alengthened height away from pivot points of the foot.

These and other aspects will become apparent to those skilled in the artafter a reading of the following description when considered with thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present disclosure are described indetail below with reference to the attached drawing figures and wherein:

FIG. 1 is a side view of an article of footwear according to oneembodiment;

FIG. 2A, FIG. 2B and FIG. 2C depict prior art footwear and the variousstages of walking and the pivot points at each stage in relation to thesubstratum of the ground;

FIG. 3 is a diagram of a side elevation view and a bottom elevation viewof the article of footwear indicating positioning of the parabolic arcs;and

FIG. 4 is an enlarged side view and bottom view of the article offootwear in FIG. 3 showing various parameters for a parabolic arc.

DETAILED DESCRIPTION

Several embodiments will be described more fully in reference to theaccompanying figures. However, this disclosure should not be construedas limited to the embodiments set forth herein. Rather, theseembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the invention to thoseskilled in the art. In the drawings, like numbers refer to like elementsthroughout. Thicknesses and dimensions of some components may beexaggerated for clarity.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be understood that when an element is referred to as being“attached,” “coupled” or “connected” to another element, it can bedirectly attached, coupled or connected to the other element orintervening elements may also be present. In contrast, when an elementis referred to as being “directly attached,” directly coupled” or“directly connected” to another element, there are no interveningelements present.

All patents, patent applications and publications referred to herein areincorporated by reference in their entirety. In case of a conflict interminology, the present specification is controlling.

It is noted that any one or more aspects or features described withrespect to one embodiment may be incorporated in a different embodimentalthough not specifically described relative thereto. That is, allembodiments and/or features of any embodiment can be combined in any wayand/or combination. Applicant reserves the right to change anyoriginally filed claim or file any new claim(s) accordingly, includingthe right to be able to amend any originally filed claim to depend fromand/or incorporate any feature of any other claim although notoriginally claimed in that manner. These and other objects and/oraspects of the present invention are explained in detail in thespecification set forth below.

Referring now to FIG. 1 , an article of footwear 10 is provided. Thearticle of footwear provides traction while reducing damage on a walkingsurface (e.g., a golf green). The article of footwear may include anupper 100 and a sole 110. The article of footwear 10 may further includea heel region 130, a forefoot region 140 and a traction system 150.

The heel region 130 may generally correspond with the rear portions of afoot, namely, the area surrounding and below the Achilles tendon, theposterior of the heel, and the talus and calcaneus bones. A forefootregion 140 may generally correspond with a front of a foot, namely, thetoes and metatarsal, phalange, and sesamoid bones. A midfoot region 135may generally correspond with a middle of the foot, namely, the arch andthe navicular, cuboid, and cuneiform bones. It is understood that theheel region 130, midfoot region 135, and forefoot region 140 areintended to represent general areas of footwear and not demarcateprecise areas.

The article of footwear 10 may have a medial side that extends from aforefoot region 140 to a heel region 130 and a lateral side that extendsfrom a forefoot region 140 to a heel region 130. The lateral side andthe medial side may be opposite one another. In some embodiments, thelateral side and medial side may be generally parallel to one another.The lateral side may generally correspond to an outside area of a footand a surface that faces away from a user's other foot. The medial sidemay generally correspond with an inside area of a foot and a surfacethat faces toward a user's other foot.

The upper 100 may have an interior surface 102 and an exterior surface104. The interior surface 102 may partially define an area configured toreceive a user's foot. The upper 100 may be configured to extend over auser's foot, along the medial and lateral sides of the foot, and arounda forefoot region and a heel region of the foot. The area configured toreceive a user's foot may be accessed from an ankle opening defined by acollar 106. The footwear 10 may include a tongue 120.

The upper 100 may be constructed from any appropriate material now knownor later developed, including, but not limited to, leather, suede,fabric, canvas, weaves, knits, man-made polymer fibers, nylon,polyester, or cotton. The upper 100 may be elastic. Alternately, atleast a portion of the upper 100 may be elastic. In other embodiments,the upper 100 may be inelastic. The upper 100 includes at least aportion that is inflexible and is rigid or semi-rigid.

The upper 100 may further include a heel counter 132 at the heel region130. The heel counter 132 may reinforce the upper 100 and limit movementof a user's heel. The heel counter 132 may wrap around the heel region130 and extend forward along both the lateral side and the medial side.

The footwear may include one or more closure systems for securing auser's foot, the selection of which is within the skill of one in theart. Examples of closure systems may include any suitable closure systemincluding conventional laces, a lace tightening system as described inU.S. Pat. No. 10,070,695 and incorporated herein by reference in itsentirety, and a closure system as described in U.S. application Ser. No.17/355,390 filed Jun. 23, 2021 and incorporated herein by reference inits entirety. For example, the closure system may comprise a lace 152above the upper 100 and configured to interact with the outer orexterior surface 104 of the upper. The lace 152 may be entirely orpartially visible. In other embodiments, the lace guides 156 may beplaced such that the lace 152 is not in direct contact with the upper100.

In some embodiments, the lace 152 may be between an exterior surface 104of the upper and an interior surface 102 of the upper. In suchembodiments there may be a channel for the laces between the exteriorsurface 104 of the upper and the interior surface 102 of the upper. Thelace guides 156 may also be positioned between the exterior surface 104of the upper and the interior surface 102 of the upper.

In some embodiments, a portion of the lace 152 may be between anexterior surface 104 of the upper and an interior surface 102 of theupper, and a portion of the lace 152 may be above an exterior surface104 of the upper.

In some embodiments, the sole 110 of the footwear 10 may include anoutsole 112, a midsole 114, and an insole (not shown). The sole 110 maybe coupled to the upper 100 at a bite line 105. The sole 110 may beconfigured to attenuate forces or provide support or cushioning. In someembodiments, the midsole 114 may be formed from a compressible materialthat provides cushioning. In other embodiments, the midsole 114 maycomprise plates or be formed from dense materials to increase stability.The outsole 112 may be below the midsole 114 and may be designed tointeract with a ground surface.

The insole may be designed to provide cushioning or comfort for a user.The insole may be removable and may be above the midsole 114 when inuse. In some embodiments, the insole may be designed to provide support.The insole may be flexible, semi-rigid, or rigid.

The outsole 112 may include a traction system 150 designed to imparttraction. In some embodiments, the traction system 150 may comprise aplurality of traction elements 158. The traction elements may bereleasably or fixedly coupled to the outsole 112. The traction elements158 may be formed or molded into elements such as a spike or nub withpolymers such as rubbers, thermoplastic polyurethanes, polyamides,ethylene-vinyl acetate, and/or SEBS. The traction elements may be anytype of traction element now known or later discovered. For example, thetraction system may comprise traction elements as disclosed in U.S.Patent Publication No. 2020/0383421, 2020/0383422, 2020/0077734, and/or2020/0146389, each of which is incorporated herein by reference in itsentirety for all purposes. In some embodiments, the traction system maycomprise a combination of different types of traction elements,including those described in the publications above.

Referring to FIGS. 2A-2C, various pivot points of golf footwear areillustrated, and show how conventional prior art traction elements diginto ground substratum S of a golf course. This digging into thesubstratum S may be damaging to the ground and particularly the groundof putting greens. In FIG. 2A, the heel of the foot contacts the greenwhile walking the golf course via traction elements 158 b on the lateralposterior edge of the heel at pivot point 162. As the heel is weighted,the traction elements penetrate the course surface. As the foot rotatesfrom heel strike to stance phase of the gait cycle, the fully penetratedheel traction elements 158 b at heel pivot point 162 rotateconcomitantly within the substratum of the green. In FIG. 2B in thestance phase, all traction elements 158 b are seated into the greensubstratum S. In FIG. 2C, the fully penetrated heel traction elements158 a begin to rotate away from the surface of the green at about pivotpoint 160 as the user pushes off of the forefoot in. During support-footforefoot dorsiflexion, the traction elements 158 a near the pivot point160 rotate in substratum S at front toe pivot point 164, resulting indigging. The present invention may avoid this damaging digging into thesubstratum S by minimizing penetration.

Referring to FIG. 3 , a solution to digging the substratum S of a greenduring walking is illustrated. In general, the footwear of the presentinvention includes reduced traction element height near contact rotationlocations (pivot points) and increased traction element height away fromcontact rotation locations. In some embodiments, the traction elements158 may form one or more parabolic arcs 170 along the outsole 112. Theparabolic arcs may be formed based on the heights of the tractionelements 158. Traction elements 158 with a shortened or minimum heightmay be positioned at the ends 182 of the parabolic arcs 170. Tractionelements 158 at the peaks 180 of the parabolic arcs may have alengthened or maximum height in relation to the other traction elements.The traction elements between the peak and ends of the parabolic arcsmay have a medium height ranging between the minimum and maximum definedheights and vary from low to high depending on placement as shown inFIG. 3 .

Outsole 112 may have a first parabolic arc 172 and a second parabolicarc 174. The parabolic arcs 170 may have identical arcs. In otherembodiments, the parabolic arcs 170 may vary in one or more ways.Referring to FIG. 4 , a first parabolic arc 172 may have a firstpredetermined length L₁ and a second parabolic arc 174 may have a secondpredetermined length L₂ and the lengths between the two may differ. Insome embodiments, a length ratio L_(R) may be defined as:

L _(R) =L ₁ :L ₂

In some embodiments, the length ratio between the first parabolic arcand the second parabolic arc may be between about 4:1 and 2:1. Forexample, the first parabolic arc 172 may have a length between about 190and 210 mm. The second parabolic arc may have a length between about 90and 110 mm. However, the length ratio may vary in other embodimentsbased on factors such as the shoe size of the article of footwear.

The parabolic arcs 170 may also vary in other manners. For example, theparabolic arcs 170 may each vary in minimum height H_(m), maximum heightH_(max), area, width, number of traction elements, density of tractionelements, curvature of both the traction element and of the sole, and/oroverall size and shape of the traction elements. Each traction element158 may have a height ranging from about 1 to 8 mm. In some embodiments,the plurality of traction elements 158 may have a minimum height H_(m)between about 1 and 4 mm. In some embodiments, the plurality of tractionelements 158 may have a maximum height H_(max) between about 4 and 7.5mm.

Certain embodiments of the outsole 112 may include parabolic arcs 170separated by one or more flat regions (not shown) on the outsole 112.For example, the flat regions may comprise traction elementssubstantially identical in height. The flat region may alternatively beformed from the outsole 112 itself.

In some embodiments, parabolic arcs 170 may be positioned based on pivotpoints 160, 162 and 164. The slope of the parabolic arcs 170 mayincrease away from pivot points 160, 162 and 164. For example, as seenin FIG. 3 , the traction elements 158 may form a first parabolic arc 172from forefoot pivot point 160 to heel pivot point 162 and a secondparabolic arc 174 from forefoot pivot point 160 to the front toe pivotpoint 164. In some embodiments, the first parabolic arc 172 may beformed within the heel region 130 and midfoot region 135. The secondparabolic arc 174 may be formed at the forefoot region 140. Someembodiments of the traction system 150 may utilize more than twoparabolic arcs 170. For example, the outsole 112 may have a firstparabolic arc 172 formed within the heel region 130, a second parabolicarc 174 formed within the forefoot region 140 and a third parabolic arc(not shown) formed within the midfoot region 135.

The arrangement of traction elements 158 as parabolic arcs 170 may beuseful for increased traction, while at the same time, minimizing damageto walking surfaces due to penetration of the substratum S. The tractionelements 158 may form parabolic arcs 170 that have the same traction asoutsoles having a substantially flat surface area that requireaggressive traction elements (e.g., higher number of traction elements,increased jaggedness and size). The parabolic arcs 170 enable hightraction regardless of the type of traction element.

One method of determining traction may be by measuring the verticalcontact area ratio V_(car) for the outsole, which is defined as:

$V_{car} = \frac{{\Sigma}_{i = 0}^{N}T_{i}}{{Surface}{Area}{for}{Bottom}{of}{Outsole}}$

wherein T is the vertical contact area for each traction element and Nis the total number of traction elements. Assuming a general cylindricalshape for each traction element 158, the contact area for each tractionelement is defined as:

T=H×D

wherein H is the height of the traction element and D is its diameter.

In some embodiments, a higher V_(car) indicates higher traction. Thus,one method for increasing traction is by increasing the total number oftraction elements to increase V_(car). Another method for increasingtraction is by increasing the contact area for each traction element,which may be done by increasing its height and/or diameter.

As seen in FIG. 4 , various parameters of the parabolic arcs 170 may bemodified to adjust traction. Examples of possible parameters may includethe length L of the parabolic arc (wherein the reference point isdefined as X=0 in FIG. 4 ), the average height of traction elements FL,the minimum height of the traction elements H_(m), and the maximumheight H_(max) of the traction elements. Articles of footwear 10 mayhave some parameters that vary with shoe size and/or may have one ormore other parameters that are identical regardless of shoe size. Forinstance, the length of the parabolic arcs 170 may vary based on shoesize, wherein longer lengths of parabolic arcs 170 may be used forlarger shoe sizes and shorter parabolic arc lengths may be used forsmaller shoe sizes. The maximum height for the traction elements 158 mayalso vary based on shoe size, wherein the maximum height may beincreased for larger shoe sizes and the maximum height may be decreasedfor smaller shoe sizes. Conversely, the minimum height may be heldconstant regardless of shoe sizes. These are merely provided asexamples, and in other embodiments, the length of the parabolic arcs andmaximum height may be held constant across shoe sizes.

The overall traction for the traction system 150 may depend on theshapes of its parabolic arcs 170. A shape factor may be defined by oneor more parameters of a parabolic arc. One example of a shape factor fora parabolic arc may be defined as

${SF} = \frac{6\left( {H_{m} - H_{r}} \right)}{L^{2}}$

wherein SF is the shape factor, H_(m) is a minimum height of theplurality of traction elements, H_(r) is an average height of theplurality of traction elements, and L is a length of the parabolic arc(L₁ or L₂). The shape factor may be correlated with the overall tractionof the traction system 150. For example, the desired traction may bewithin a shape factor range. In some embodiments, the preferred shapefactor for a first parabolic arc 172 may be between about −0.00015 and−0.00045. In some embodiments, the preferred shape factor for a secondparabolic arc may be between −0.0006 and −0.00018. These ranges arebased on embodiments wherein the first parabolic arc 172 is positionedbetween a heel pivot point 162 and a forefoot pivot point 160 and thesecond parabolic arc 174 is positioned between the forefoot pivot point160 and a front toe pivot point 164. Other embodiments may utilize ashape factor defined differently than the expression given above.

The preferred shape factor range may vary depending on one or moreparameters, including shoe size, traction element size and the totalnumber of parabolic arcs for a traction system. For example, the lengthof a parabolic arc may be increased for larger shoe sizes and thereforethe desired shape factor may be greater than that of a parabolic arc fora traction system on a smaller shoe size. Changes in the averagetraction element height and/or maximum height of a traction element mayalso modify the overall shape of the parabolic arc and the desired shapefactor range.

The lengths of parabolic arcs may be decreased for traction systemshaving a higher number of parabolic arcs. For example, one or moreparabolic arcs for a traction system having a total of three parabolicarcs may be shorter than one or more corresponding parabolic arcs for atraction system having only two parabolic arcs in total. Thus, the shapefactors for these shorter parabolic arcs would also be decreased.However, a higher number of parabolic arcs does not necessarily indicatethat all parabolic arcs within that traction system are decreased inlength than a traction system with a lower number of parabolic arcs. Itis contemplated that certain parabolic arcs may still have a largerlength in traction systems despite having a greater number of parabolicarcs.

Many different arrangements of the various components depicted, as wellas components not shown, are possible without departing from the spiritand scope of the present disclosure. Embodiments of the presentdisclosure have been described with the intent to be illustrative ratherthan restrictive. Alternative embodiments will become apparent to thoseskilled in the art that do not depart from its scope. A skilled artisanmay develop alternative means of implementing the aforementionedimprovements without departing from the scope of the present disclosure.

It will be understood that certain features and combinations are ofutility and may be employed without reference to other features andcombinations and are contemplated within the scope of the claims

What is claimed is:
 1. An article of footwear, comprising: an upper; anoutsole comprising a plurality of pivot points including a front toepivot point, a heel pivot point, and a forefoot pivot point locatedbetween the front toe pivot point and the heel pivot point, wherein theplurality of pivot points corresponds to a plurality of locations on theoutsole about which the article of footwear is configured to rotatewhile contacting a ground surface; a midsole, and a plurality oftraction elements comprising (i) a first set of traction elementsextending between the heel pivot point and the forefoot pivot point and(ii) a second set of traction elements extending between the forefootpivot point and the front toe pivot point, the first set of tractionelements having different heights ranging from (i) a first minimumheight at or near the heel and forefoot pivot points to (ii) a firstmaximum height at or near a first midpoint between the heel and forefootpivot points, wherein all of the traction elements in the first set oftraction elements extend away from the outsole to a first plurality ofpoints that lie along a first parabolic arc extending from the heelpivot point to the forefoot pivot point, the first plurality of pointspositioned at a first plurality of distances from the outsole, the firstplurality of distances corresponding to the different heights of thefirst set of traction elements, wherein the first maximum heightcorresponds to a peak of the first parabolic arc, and wherein the firstminimum height corresponds to one or more ends of the first parabolicarc, and the second set of traction elements having different heightsranging from (i) a second minimum height at or near the forefoot andfront toe pivot points to (ii) a second maximum height at or near asecond midpoint between the forefoot and front toe pivot points, whereinall of the traction elements in the second set of traction elementsextend away from the outsole to a second plurality of points that liealong a second parabolic arc extending from the forefoot pivot point tothe front toe pivot point, the second plurality of points positioned ata second plurality of distances from the outsole, the second pluralityof distances corresponding to the different heights of the second set oftraction elements, wherein the second maximum height corresponds to apeak of the second parabolic arc, and wherein the second minimum heightcorresponds to one or more ends of the second parabolic arc, wherein thefirst maximum height is greater than the second maximum height.
 2. Thearticle of footwear of claim 1, wherein the first set of tractionelements comprises (i) a first traction element and a second tractionelement positioned at the one or more ends of the first parabolic arcand (ii) a third traction element positioned at the first midpoint,wherein the first traction element and the second traction element havea low height, and wherein the third traction element has a high heightthat is greater than the low height.
 3. The article of footwear of claim2, wherein the first set of traction elements comprises one or moreadditional traction elements positioned between (i) the first or secondtraction element and (ii) the third traction element, the one or moreadditional traction elements having a medium height that is greater thanthe low height and less than the high height.
 4. The article of footwearof claim 2, wherein the second set of traction elements comprises alengthened traction element positioned at the second midpoint, thelengthened traction element having a medium height that is greater thanthe low height and less than the high height.
 5. The article of footwearof claim 4, wherein the second set of traction elements comprises one ormore additional traction elements positioned between (i) the lengthenedtraction element and (ii) the one or more ends of the second parabolicarc, the one or more additional traction elements having a height thatis greater than the low height and less than the medium height.
 6. Thearticle of footwear of claim 2, wherein the third traction elementcomprises a lengthened traction element having a greater height than anyother traction element in the second set of traction elements.
 7. Thearticle of footwear of claim 1, wherein a height of the first set oftraction elements gradually increases from (i) the heel and forefootpivot points to (ii) the first midpoint between the heel and forefootpivot points.
 8. The article of footwear of claim 1, wherein a height ofthe second set of traction elements gradually increases from (i) theforefoot and front toe pivot points to (ii) the second midpoint betweenthe forefoot and front toe pivot points.
 9. The article of footwear ofclaim 1, wherein a height of the first set of traction elementsgradually decreases from (i) the first midpoint to (ii) the heel andforefoot pivot points.
 10. The article of footwear of claim 1, wherein aheight of the second set of traction elements gradually decreases from(i) the second midpoint to (ii) the forefoot and front toe pivot points.11. The article of footwear of claim 1, wherein each traction elementbetween the peak of the first or second parabolic arc and the one ormore ends of the first or second parabolic arc has a different heightdepending on a distance between (i) each traction element and (ii) thepeak or the one or more ends of the first or second parabolic arc. 12.The article of footwear of claim 1, wherein the plurality of tractionelements have a minimum height between 1 mm and 4 mm and a maximumheight between 4 mm and 7.5 mm.
 13. The article of footwear of claim 1,wherein the first set of traction elements includes a plurality ofspikes positioned in an arch region or a midfoot region of the outsole,wherein the plurality of spikes includes at least one spike with aheight corresponding to the first maximum height.
 14. The article offootwear of claim 1, wherein the first set of traction elements isformed within a heel region and a midfoot region of the outsole, andwherein the second set of traction elements is formed within a forefootregion of the outsole.
 15. The article of footwear of claim 1, whereinthe first set of traction elements and the second set of tractionelements are separated or spaced apart by one or more flat orsubstantially flat regions.
 16. The article of footwear of claim 15,wherein the one or more flat or substantially flat regions correspond to(i) a portion of the outsole or (ii) a third set of traction elementswith a substantially identical or uniform height.
 17. The article offootwear of claim 1, wherein the outsole comprises a central portion anda peripheral portion extending around the central portion, wherein theperipheral portion includes the first and second sets of tractionelements, and wherein the central portion includes one or more flatsurface areas that do not include any traction elements.
 18. The articleof footwear of claim 1, wherein the first set of traction elementsextends along a first length L₁ of the outsole, and wherein the secondset of traction elements extends along a second length L₂ of theoutsole, wherein L₁ is greater than L₂.
 19. The article of footwear ofclaim 1, wherein the first set of traction elements and the second setof traction elements include a combination of different types oftraction elements.
 20. The article of footwear of claim 1, wherein theplurality of traction elements comprise a rubber material and athermoplastic polyurethane (TPU) material.